Reciprocal expression in CD4 or CD8 subsets of different members of the V alpha 11 gene family correlates with sequence polymorphism

Previous staining studies with TCR V alpha 11-specific mAbs showed that V a lpha 11.1/11.2 (AV11S1 and S2) expression was selectively favored in the CD 4(+) peripheral T cell population, As this phenomenon was essentially indep endent of the MHC haplotype, it was suggested that AV11S1 and S2 TCRs exert a preference for recognition of class II MHC molecules, The V alpha segmen t of the TCR alpha-chain is suggested to have a primary role in shaping the T cell repertoire due to selection for class I or II molecules acting thro ugh the complementarity determining regions (CDR) 1 alpha and CDR2 alpha re sidues. We have analyzed the repertoire of V alpha 11 family members expres sed in C57BL/6 mice and have identified a new member of this family; AV11S8 , We show that, whereas AV11S1 and S2 are more frequent in CD4(+) cells, AV 11S3 and S8 are more frequent in CD8(+) cells. The sequences in the CDR1 al pha and CDR2 alpha correlate with differential expression in CD4(+) or CD8( +) cells, a phenomenon that is also observed in BALB/c mice. With no appare nt restriction in TCR J alpha usage or CDR3 alpha length in C57BL/6, these findings support the idea of V alpha-dependent T cell repertoire selection through preferential recognition of MHC class I or class II molecules.